The present invention relates to a technology for controlling disturbance in a probe for measuring current.
With an electronic device, and so forth, it is effective to cause the enclosure of the electronic device to be electromagnetically shielded to thereby control a level of unwanted electromagnetic-radiation generated by a circuit board in order to confine the unwanted electromagnetic-radiation generated by the circuit board inside the electronic device, and prevent leakage thereof to outside the electronic device.
The inventor, et al. have thus far disclosed a magnetic field probe, or a measuring technique and a measuring instrument, serving as a support technology for reducing the unwanted electromagnetic-radiation generated by the circuit board, as described in Japanese Unexamined Patent Application Publication No. 2002-156430, and Japanese Unexamined Patent Application Publication No. 2003-279611, respectively.
One of these patent documents, namely, Japanese Unexamined Patent Application Publication No. 2002-156430 relates to a magnetic field probe (What is claimed is:) provided with a shield disposed around a magnetic field detection coil with magnetic fluxes interlinked with coil in as-secured state, and Japanese Unexamined Patent Application Publication No. 2003-279611 relates to an electromagnetic-wave emission-source search device having a magnetic field probe for measuring magnetic field distribution in the vicinity of a three-dimensional enclosure, a means for moving or rotating the probe in the directions of x, y, z, θ, and φ, respectively, a means for finding current distribution from the magnetic field distribution, and a means for finding electric field strength at desired distances from the current distribution.
With these devices, a position of a current which is a source of electromagnetic radiation is identified by measuring the magnetic field distribution in the vicinity above the circuit board to be thereby used in review for the purpose of reducing electromagnetic radiation from the circuit board.